NAME¶
explain_pread_or_die - seek and read from a file descriptor and report errors
SYNOPSIS¶
#include <libexplain/pread.h>
ssize_t explain_pread_or_die(int fildes, void *data, size_t data_size, off_t
offset);
ssize_t explain_pread_on_error(int fildes, void *data, size_t data_size, off_t
offset))
DESCRIPTION¶
The
explain_pread_or_die function is used to call the
pread(2)
system call. On failure an explanation will be printed to
stderr,
obtained from the
explain_pread(3) function, and then the process
terminates by calling exit(EXIT_FAILURE).
The
explain_pread_on_error function is used to call the
pread(2)
system call. On failure an explanation will be printed to
stderr,
obtained from the
explain_pread(3) function, but still returns to the
caller.
- fildes
- The fildes, exactly as to be passed to the pread(2)
system call.
- data
- The data, exactly as to be passed to the pread(2)
system call.
- data_size
- The data_size, exactly as to be passed to the
pread(2) system call.
- offset
- The offset, exactly as to be passed to the pread(2)
system call.
RETURN VALUE¶
The
explain_pread_or_die function only returns on success, see
pread(2) for more information. On failure, prints an explanation and
exits, it does not return.
The
explain_pread_on_error function always returns the value return by
the wrapped
pread(2) system call.
EXAMPLE¶
The
explain_pread_or_die function is intended to be used in a fashion
similar to the following example:
ssize_t result = explain_pread_or_die(fildes, data, data_size, offset);
SEE ALSO¶
- pread(2)
- read from a file descriptor at a given offset
- explain_pread(3)
- explain pread(2) errors
- exit(2)
- terminate the calling process
COPYRIGHT¶
libexplain version 0.52
Copyright (C) 2009 Peter Miller